Magnetic chuck.



W..S. GRIFFITH.

MAGNETIC CHUCK.

APPLICATION FILED JUNE24. 1913.

Patented July 10, 1917.

Z 23 Z Z1 /fizesses UNITED STATES PATENT oEEioE.

WINFRED S. GRIFFITH, OF WORCESTER, MASSACHUSETTS, ASSIGNOR TO HEALD MACHINE COMPANY, OF WORCESTER, MASSACHUSETTS, A CORPORATION OF MASSACHUSETTS.

MAGNETIC CHUCK.

Application filed June 24, 1913.

To all whom it may concern:

Be it known that I, WINFRED S. GRIFFITH, a citizen of the United States, residing at Worcester, in the county of Worcester, State of Massachusetts, have invented a certain new and useful Improvement in Magnetic- Chucks, of which the following is a specification, reference being had therein to the accompanying drawings.

This invention relates to rotary chucks but more particularly to those of the magnetic type and has for its object to provide a structure which shall be more durable and more eflicient than any device of a similar nature heretofore known.

In the forms of chucks now in common use, electro-magnets having cast iron faces are seated in the body of the chuck and these faces are generally in the form of a sector of a circle. These faces. soon wear OE and their holding action is comparatively weak.

In order to obviate these difiiculties, a chuck has been devised in which the operating faces of the magnetic members are of magnet steel and of a peculiar form which will be fully described hereinafter and which produces great holding power.

The many other features and advantages of the invention will be fully described hereinafter and included in the claim.

One embodiment of the invention is shown in the drawings in which I Figure 1 is a plan view of the invention complete, and

Fig. 2 a section on the line 2-2 of Fig. 1. Referring to the drawings, the device is shown to comprise a body portion 10 in which are set a plurality of electro-magnets 11 having their operating faces 12 elongated. Each of these magnets comprises a plate from which projects at substantially a.

retaining plat e 15 by means of screws 16.

Similar screws 17 secure the base of each of the magnet members 11 to this plate 15.

Specification of Letters Patent.

Serial No. 775,455.

No broad claim is made by the applicant to a chuck composed of a body having magnet. members mounted therein as this is known to be old, but the form of the magnet members and the method of mounting them in this body is believed to be new and produces a very advantageous result.

By making the operating plates long and narrow, an extremely large holding surface is obtained and a much more powerful hold may be obtained by the chuck than where these plates are otherwise formed. These plates are preferably set parallel to one another in the body and may be integral with the flanges 13 or secured thereto in any desired Way.

At the rear face of the plate 15 is secured a sleeve 18 of wood or other substantially non-conducting material and upon this sleeve are set two electrical contact rings 19 and 20 of copper Or other suitable conducting material.

The wire coils enveloping the magnets are the magnet members detached from the plateand secured thereto, the plate may be made of any suitable material and the steel members may be produced at small expense. Also any one may be replaced without replacing the whole.

This chuck is constructed to be attached to the live spindle of a lathe in the manner usual to rotary chucks.

The applicant is aware that a large number of changes in the construction and arrangement of parts might be made by any one skilled in the art without departing from the scope of his invention as defined by the appended claim and hedoes not care to be limited to the particular embodiment herein shown and described.

Patented July 10, 1917.

What I claim as my invention and desire' extension core in each of said slots insertible In testimony whereof I aifix my signatnre from the rear, an energizing coil for each of in the presence of two Witnesses.

said cores, a retaining plate secured to the WINFRED S. GRIFFITH. rear face of such body, and means for fas- Witnesses: 5 tening the rear end of each of said cores to 'HANNAH M. KENNEDY,

the front face of said plate. KATHERINE E. RYAN. 

